Spatial Averaging of Transmission Power to Reduce Power Cutbacks

Abstract

Techniques and devices for spatial averaging of transmission power to reduce power cutbacks are described. The techniques of spatial averaging may enable separate determinations of transmit power capacities for each antenna of a computing device if each antenna is spaced apart from a neighboring antenna by a minimum distance. The transmit power capacities may be based on transmit power limits and, in general, may be determined independently from, or with reduced dependence on, a transmit power of another antenna. These separate determinations may allow for spatial averaging of transmission power of a device to improve antenna-switching decisions and reduce a dependence upon power cutbacks. When power cutbacks are unavoidable, the separate determinations may additionally improve antenna-switching decisions at cutback powers to optimize the transmission power of the device.

1 . A method comprising:
 determining a first transmit power capacity based on a first transmit power limit for a first antenna of a computing device, the computing device configured to transmit signals at a first transmit power using the first antenna, the first transmit power limited by the first transmit power limit;   determining a second transmit power capacity based on a second transmit power limit for a second antenna of the computing device, the computing device further configured to transmit signals at a second transmit power using the second antenna, the second transmit power limited by the second transmit power limit, the second transmit power capacity determined using the second transmit power and with less dependence on the first transmit power when compared to dependence on the second transmit power;   comparing the first transmit power capacity and the second transmit power capacity to determine which of the first and second transmit power capacities has a lesser or greater transmit power capacity; and   responsive to the first transmit power capacity having the lesser transmit power capacity or the second transmit power capacity having the greater transmit power capacity, switching a current or planned transmission from the first antenna to the second antenna.   
     
     
         2 . The method as recited by  claim 1 , wherein the first antenna is spaced apart from the second antenna by an antenna separation, the antenna separation configured to enable:
 the first transmit power capacity to be determined independently from the second transmit power, the independent determination of the first transmit power capacity effective to reduce the less dependence on the second transmit power to be no dependence on the second transmit power; and   the second transmit power capacity to be determined independently from the first transmit power, the independent determination of the second transmit power capacity effective to reduce the less dependence on the first transmit power to be no dependence on the first transmit power.   
     
     
         3 . The method as recited by  claim 1 , wherein the switching of the current or planned transmission from the first antenna to the second antenna is responsive to a power difference between the lesser transmit power capacity and the greater transmit power capacity being greater than or equal to a trigger threshold. 
     
     
         4 . The method as recited by  claim 1 , wherein:
 the switching of the current or planned transmission from the first antenna to the second antenna comprises:
 stopping the current or planned transmission from the first antenna; and 
 transmitting or planning transmission of signals using the second antenna; and 
   the method further comprises:
 responsive to transmitting signals using the second antenna, determining that a third transmit power capacity of the first antenna is greater than a fourth transmit power capacity of the second antenna; and 
 responsive to the determining, switching transmission from the second antenna to the first antenna. 
   
     
     
         5 . The method as recited by  claim 1 , wherein:
 the determining of the first transmit power capacity comprises averaging the first transmit power over a duration of time; and   the determining of the second transmit power capacity comprises averaging the second transmit power over the duration of time.   
     
     
         6 . The method as recited by  claim 5 , further comprising:
 averaging the first transmit power limit over the duration of time to determine a first MTPL of the first antenna, wherein the determining of the first transmit power capacity is based on the first MTPL; and   averaging the second transmit power limit over the duration of time to determine a second MTPL of the second antenna, wherein the determining of the second transmit power capacity is based on the second MTPL.   
     
     
         7 . The method as recited by  claim 6 , further comprising:
 receiving a first reference signal receiver power, RSRP, of the first antenna, wherein the determining of the first transmit power capacity is based on the first RSRP and the first MTPL; and   receiving a second RSRP of the second antenna, wherein the determining of the second transmit power capacity is based on the second RSRP and the second MTPL.   
     
     
         8 . The method as recited by  claim 6 , further comprising:
 detecting a decrease in the first MTPL to a third MTPL;   responsive to the detected decrease:
 reducing the first transmit power capacity based on the third MTPL without reducing the second transmit power capacity; and 
 reducing the first average transmit power to a first cutback power, the first cutback power limited by the third MTPL. 
   
     
     
         9 . The method as recited by  claim 8 , further comprising:
 responsive to determining that the first cutback power is greater than a minimum power threshold, determining whether a first power difference is greater than a trigger threshold to perform antenna switching, the first power difference determined by comparing the reduced first transmit power capacity to the second transmit power capacity; and   responsive to determining that the first power difference is greater than the trigger threshold, performing the switching by:
 stopping the current or planned transmission from the first antenna; and 
 transmitting or planning transmission of signals using the second antenna. 
   
     
     
         10 . The method as recited by  claim 6 , further comprising:
 detecting a decrease in the second MTPL to a fourth MTPL;   responsive to the detected decrease:
 reducing the second transmit power capacity based on the fourth MTPL without reducing the first transmit power capacity; and 
 reducing the second average transmit power to a second cutback power, the second cutback power limited by the fourth MTPL. 
   
     
     
         11 . The method as recited by  claim 10 , further comprising:
 responsive to determining that the second cutback power is greater than a minimum power threshold, determining whether a second power difference is greater than a trigger threshold to perform antenna switching, the second power difference determined by comparing the reduced second transmit power capacity to the first transmit power capacity; and   responsive to determining that the second power difference is greater than the trigger threshold, performing a second antenna switch by:
 stopping the current or planned transmission from the first antenna; and 
 transmitting or planning transmission of signals using the second antenna. 
   
     
     
         12 . The method as recited by  claim 1 , wherein:
 the first transmit power limit corresponds to a first regulatory limit for the first antenna to transmit radio-frequency signals; and   the second transmit power limit corresponds to a second regulatory limit for the second antenna to transmit radio-frequency signals.   
     
     
         13 . The method as recited by  claim 1 , wherein the first antenna is spaced apart from the second antenna by an antenna separation, the antenna separation configured to enable:
 the second transmit power capacity to be determined with similar dependence on the first transmit power when compared to dependence on the second transmit power; and   the first transmit power capacity to be determined with similar dependence on the second transmit power when compared to dependence on the first transmit power.   
     
     
         14 . The method as recited by  claim 1 , further comprising:
 determining a third transmit power capacity based on a third transmit power limit for a third antenna of the computing device, the computing device further configured to transmit signals at a third transmit power using the third antenna, the third transmit power limited by the third transmit power limit, the third transmit power capacity determined using the third transmit power and with less dependence on the first transmit power and the second transmit power when compared to dependence on the third transmit power; and   performing antenna switching, responsive to comparing the third transmit power capacity to the first transmit power capacity or the second transmit power capacity.   
     
     
         15 . A computing device comprising:
 an enclosure;   a first antenna and a second antenna, the first antenna and the second antenna positioned within the enclosure and configured to receive and transmit signals;   at least one processor; and   computer-readable storage media comprising that, responsive to execution by the at least one processor, implement a maximum transmit power level (MTPL) controller to:
 determine a first transmit power capacity based on a first transmit power limit for the first antenna of the computing device, the computing device configured to transmit signals at a first transmit power using the first antenna, the first transmit power limited by the first transmit power limit; 
 determine a second transmit power capacity based on a second transmit power limit for the second antenna of the computing device, the computing device further configured to transmit signals at a second transmit power using the second antenna, the second transmit power limited by the second transmit power limit, the second transmit power capacity determined using the second transmit power and with less dependence on the first transmit power when compared to dependence on the second transmit power; 
 compare the first transmit power capacity and the second transmit power capacity to determine which of the first and second transmit power capacities has a lesser or greater transmit power capacity; and 
 in response to the first transmit power capacity having the lesser transmit power capacity or the second transmit power capacity having the greater transmit power capacity, switch a current or planned transmission from the first antenna to the second antenna. 
   
     
     
         16 . The computing device as recited by  claim 15 , wherein the first antenna is spaced apart from the second antenna by an antenna separation, the antenna separation configured to:
 enable the MTPL controller to determine the first transmit power capacity independently from the second transmit power, the independent determination of the first transmit power capacity by the MTPL controller effective to reduce the less dependence on the second transmit power to be no dependence on the second transmit power; and   enable the MTPL controller to determine the second transmit power capacity independently from the first transmit power, the independent determination of the second transmit power capacity by the MTPL controller effective to reduce the less dependence on the first transmit power to be no dependence on the first transmit power.   
     
     
         17 . The computing device as recited by  claim 15 , wherein the switch of the current or planned transmission from the first antenna to the second antenna by the MTPL controller is in response to a power difference between the lesser transmit power capacity and the greater transmit power capacity being greater than or equal to a trigger threshold. 
     
     
         18 . The computing device as recited by  claim 15 , wherein to switch the current or planned transmission from the first antenna to the second antenna, the MTPL controller:
 stops the current or planned transmission from the first antenna; and   transmits or plan transmissions of signals using the second antenna; and   the MTPL controller is further implemented to:
 in response to transmission of the signals using the second antenna, determine that a third transmit power capacity of the first antenna is greater than a fourth transmit power capacity of the second antenna; and 
 in response to the determination, switch transmission from the second antenna to the first antenna. 
   
     
     
         19 . The computing device as recited by  claim 15 , wherein
 the determination of the first transmit power capacity comprises averaging the first transmit power over a duration of time; and   the determination of the second transmit power capacity comprises averaging the second transmit power over the duration of time.   
     
     
         20 . The computing device as recited by  claim 19 , wherein the MTPL controller is further implemented to:
 average the first transmit power limit over the duration of time to determine a first MTPL of the first antenna, wherein the determination of the first transmit power capacity is based on the first MTPL; and   average the second transmit power limit over the duration of time to determine a second MTPL of the second antenna, wherein the determination of the second transmit power capacity is based on the second MTPL.